Bailey: 11. If we were not troubled by our suspicions of the phenomena of the sky, and about death, fearing that it concerns us, and also by our failure to grasp the limits of pains and desires, we should have no need of natural science.
Greek: 11 Εἰ μηθὲν ἡμᾶς αἱ τῶν μετεώρων ὑποψίαι ἠνώχλουν καὶ αἱ περὶ θανάτου, μή ποτε πρὸς ἡμᾶς ᾖ τι, ἔτι τε τὸ μὴ κατανοεῖν τοὺς ὅρους τῶν ἀλγηδόνων καὶ τῶν ἐπιθυμιῶν, οὐκ ἂν προσεδεόμεθα φυσιολογίας. φυσιολογίας < φῠ́σῐς f (genitive φῠ́σεως); third declension origin, birth nature, quality, property later, the nature of one's personality: temper, disposition form, shape that which is natural: nature type, kind Nature, as an entity, especially of productive power
Hicks translation: 11 If we had never been molested by alarms at celestial and atmospheric phenomena, nor by the misgiving that death somehow affects us, nor by neglect of the proper limits of pains and desires, we should have had no need to study natural science.
Saint-Andre translation: 11 If our suspicions about astronomical phenomena and about death were nothing to us and troubled us not at all, and if this were also the case regarding our ignorance about the limits of our pains and desires, then we would have no need for studying what is natural.
St-Andre note: Because the term "natural philosophy" is somewhat outdated in English, I translate φυσιολογία as "the study of what is natural" (not "the study of nature", which today implies the physical sciences instead of what is of greatest interest to Epicurus: human nature).